Nonproportional Intentionally Mistuned Turbine Blisk Design with Improved Component Modal Synthesis

An improved component modal synthesis-based nonproportional mistuning method (ICMS-NPMM) is proposed to investigate mistuned turbine blisks (MTBs) since the high-fidelity finite element models (HFEMs) involve large number of computations, which leads to low calculation efficiency. To reduce degrees of freedom and suppress the flutter of MTB, it is divided into mistuned blade structure and tuned disk structure, and the intentional mistuning is considered. Furthermore, the mistuned parameters, nonproportional mistuning, and complex loads are also considered. Firstly, the basic theory of ICMS-NPMM is investigated; secondly, the model of MTB is established via ICMS-NPMM; finally, the intentionally mistuned design of modal shape amplitudes (MSAs) is investigated via ICMS-NPMM. The results indicate that the calculation efficiency is enhanced via ICMS-NPMM relative to that of via HFEM. In addition, the sensitivity and the flutter are decreased; meanwhile, the amplitude fluctuations of MSAs are distinctly decreased and become comparatively smooth. This investigation provides an important guidance for the vibration characteristic study of complex mechanical structures in engineering practice.

Automated summary

An improved nonproportional mistuning method, ICMS-NPMM, is proposed to study mistuned turbine blisks, aiming to enhance calculation efficiency and reduce flutter. By dividing MTBs into mistuned blade and tuned disk structures, intentional mistuning is considered, leading to decreased sensitivity and flutter as well as smoother amplitude fluctuations of MSAs. The investigation provides important guidance for studying vibration characteristics of complex mechanical structures in engineering practice.